The present application claims the benefit of Korean Patent Application No. P2000-84115 filed Dec. 28, 2000, under 35 U.S.C. xc2xa7119.
1. Field of the Invention
The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display (LCD) with an electric graphic input panel (EGIP).
2. Discussion of the Related Art
In general, an LCD is provided with a liquid crystal panel having liquid crystal injected between upper and lower glass substrates, polarization plates on both sides of the liquid crystal panel for polarizing a light, a light source for generating the light, and a light plate for supplying a back light to the liquid crystal panel to display an external picture signal.
The lower glass substrate of the liquid crystal panel is provided with a plurality of gate lines extending in one direction at fixed intervals, data lines formed perpendicular to the gate lines at fixed intervals to define pixel regions, a matrix of the pixel regions between the gate lines and the data lines, a pixel electrode in each of the pixel regions, and a thin film transistor (TFT) in each of the pixel regions and having a gate electrode connected to the corresponding gate line, a source electrode connected to the corresponding data line, and a drain electrode connected to the pixel electrode. The TFT is turned on/off in response to a signal on the gate line. The upper glass substrate is provided with a color filter layer, a black matrix layer, and/or a common electrode. The upper and lower glass substrates are bonded together with a gap between the two substrates, into which the liquid crystal is injected.
The foregoing LCD is also provided with a device called EGIP (Electric Input Graphic Panel) for displaying a picture and providing an electrical graphics signal to the displayed picture. An LCD system fitted with an EGIP POL will be explained. FIG. 1 illustrates a section of a related art integrated type EGIP POL 12, and FIG. 2 illustrates a sectional view of a related art LCD with the EGIP POL of FIG. 1.
Referring to FIG. 1, integrated type EGIP POL 12 according to the related art is provided with PET (Polyethylene terephthalate) films 1 and 2 bonded together with a gap therebetween, and a transparent electrode ITO 3 or 4 formed on the opposite su faces of the PET films 1 and 2. There is a PVA (Polyvinyl Alcohol) film 5 under the lower PET film 2 for polarizing a light, a TAC (Triacetyl Cellulose) film 6 under the PVA film 5 for protecting the PVA film 5 from humidity and the like and a sliver line layer A/G 7 on the upper PET film 1. In the above EGIP POL 12, the PVA film 5 and the TAC film 6 are called as POL (Polarizer) collectively, and the PET films 1 and 2 and the A/G layer 7 are called as an EGIP film collectively.
A related art LCD with the EGIP POL of FIG. 1 is illustrated in FIG. 2.
As explained, the related art LCD with the EGIP POL is provided with a liquid crystal panel 11 having the upper and lower substrates and the liquid crystal layer therebetween, the integrated type EGIP POL 12 fitted on the liquid crystal panel 11, a lower polarization plate 13 fitted under the liquid crystal panel 11, and a top case 16 having a light plate 14 under the lower polarization plate 13 and a light source 15 for providing the light to the light plate 14. The tope case 16 cases the integrated type EGIP POL 12, the liquid crystal panel 11, the lower polarization plate 13, the light plate 14, and the light source 15. This related art LCD with the EGIP POL is identical to a general LCD if the EGIP POL 12 is removed. Accordingly, the related art LCD with the EGIP POL is a general LCD provided with the EGIP POL 12 all encased with the top case 16.
The size of the EGIP POL 12 is the same as the size of the upper plate of the liquid crystal panel 11. The EGIP POL 12 is provided with electrode wirings such as a four lined resistance film type as shown in FIGS. 3A and 3B to provide a touch panel function. For example, as shown in FIG. 3A, the transparent electrode ITO 3 attached to the upper PET film 1 as shown in FIG. 1 has two silver (Ag) wirings X1 and X2 at opposite ends thereof in an X-axis direction. As shown in FIG. 3B, the transparent electrode ITO 4 attached to the lower PET film 2 has two silver (Ag) wirings Y1 and Y2 at opposite ends thereof in a Y-axis direction. Each silver wiring is formed in a dead space (approximately 2-3 mm) part of the LCD (FIG. 2) in one direction. Data can be applied to the LCD through the electrode wirings without a keyboard or a mouse and the LCD can display a picture signal and have a function of a touch panel. The touch panel of the four lined resistance film type requires two signal readings for detecting a position, i.e., one reading to read an X-axis value, and another reading to read a Y-axis value.
However, the foregoing related art LCD with the EGIP POL has the following problems.
First, although the top case 16 encasing the EGIP POL serving as the touch panel helps to reduce malfunctions and errors to the LCD, it is difficult to repair the EGIP if it becomes defective, because the repair is complicated since the top case needs to be disassembled to access the EGIP.
Second, the dead space of the LCD is limited to be below 2-3 mm because a larger dead space for providing an adequate wiring space reduces a display area. Therefore, the formation of the touch panel electrodes in the limited dead space results in a high probability of electric short occurrences between the touch panel electrodes.
Third, although the electrode wiring having a multi-lined resistance film type, rather than the four lined resistance film type, can provide a faster response, the limited dead space impedes formation of the electrode wiring having the multi-lined resistance film type in the LCD.
Accordingly, the present invention is directed to an LCD with an EGIP that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide an LCD with an EGIP, which permits an easy repair of the EGIP and formation of five lined resistance film type wiring.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a liquid crystal display with an EGIP (Electric Graphic Input Panel) according to an embodiment of the present invention includes the LCD having a liquid crystal panel, a light plate and a light source, a case for encasing the LCD, and an integrated type EGIP POL fitted over the liquid crystal panel and the case.
In one aspect of the present invention, there is provided an LCD with an EGIP, including a liquid crystal panel having a lower substrate with a dummy pad formed thereon, a light plate, and a light source for supplying a back light to the liquid crystal panel; a case for encasing the lower substrate of the liquid crystal panel, the light plate, and the light source; and an integrated type EGIP POL fitted over the liquid crystal panel and the case.
In another aspect of the present invention, there is provided an LCD with an EGIP including a separated POL, the LCD having a liquid crystal panel, a light plate and a light source, a case for encasing the separated POL and the LCD, and an EGIP film fitted over the separated POL and the case.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.